/**
 * Copyright (c) 2005-2006, Sun Microsystems, Inc
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following 
 *     disclaimer in the documentation and/or other materials provided 
 *     with the distribution.
 *   * Neither the name of the TimingFramework project nor the names of its
 *     contributors may be used to endorse or promote products derived 
 *     from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.chen.time.timing.interpolation;

import java.util.ArrayList;
import java.util.List;

/**
 * Stores a list of times from 0 to 1 (the elapsed fraction of an animation
 * cycle) that are used in calculating interpolated values for PropertySetter
 * given a matching set of KeyValues and Interpolators for those time intervals.
 * In the simplest case, a KeyFrame will consist of just two times in KeyTimes:
 * 0 and 1.
 * 
 * @author Chet
 */
public class KeyTimes {

	private ArrayList<Float> times = new ArrayList<Float>();

	/**
	 * Creates a new instance of KeyTimes. Times should be in increasing order
	 * and should all be in the range [0,1], with the first value being zero and
	 * the last being 1
	 * 
	 * @throws IllegalArgumentException
	 *             Time values must be ordered in increasing value, the first
	 *             value must be 0 and the last value must be 1
	 */
	public KeyTimes(float... times) {
		if (times[0] != 0) {
			throw new IllegalArgumentException("First time value must" + " be zero");
		}
		if (times[times.length - 1] != 1.0f) {
			throw new IllegalArgumentException("Last time value must" + " be one");
		}
		float prevTime = 0;
		for (float time : times) {
			if (time < prevTime) {
				throw new IllegalArgumentException("Time values must be" + " in increasing order");
			}
			this.times.add(time);
			prevTime = time;
		}
	}

	List getTimes() {
		return times;
	}

	int getSize() {
		return times.size();
	}

	/**
	 * Returns time interval that contains this time fraction
	 */
	int getInterval(float fraction) {
		int prevIndex = 0;
		for (int i = 1; i < times.size(); ++i) {
			float time = times.get(i);
			if (time >= fraction) {
				// inclusive of start time at next interval. So fraction==1
				// will return the final interval (times.size() - 1)
				return prevIndex;
			}
			prevIndex = i;
		}
		return prevIndex;
	}

	float getTime(int index) {
		return times.get(index);
	}
}